summaryrefslogtreecommitdiffstats
path: root/drivers/tty/serial/8250/8250_pxa.c
blob: b9bcbe20a2be173af6a8a35e0fc2eaa39ae843b2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
// SPDX-License-Identifier: GPL-2.0+
/*
 *  drivers/tty/serial/8250/8250_pxa.c -- driver for PXA on-board UARTS
 *  Copyright:	(C) 2013 Sergei Ianovich <ynvich@gmail.com>
 *
 *  replaces drivers/serial/pxa.c by Nicolas Pitre
 *  Created:	Feb 20, 2003
 *  Copyright:	(C) 2003 Monta Vista Software, Inc.
 *
 *  Based on drivers/serial/8250.c by Russell King.
 */

#include <linux/device.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/serial_8250.h>
#include <linux/serial_core.h>
#include <linux/serial_reg.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/pm_runtime.h>

#include "8250.h"

struct pxa8250_data {
	int			line;
	struct clk		*clk;
};

static int __maybe_unused serial_pxa_suspend(struct device *dev)
{
	struct pxa8250_data *data = dev_get_drvdata(dev);

	serial8250_suspend_port(data->line);

	return 0;
}

static int __maybe_unused serial_pxa_resume(struct device *dev)
{
	struct pxa8250_data *data = dev_get_drvdata(dev);

	serial8250_resume_port(data->line);

	return 0;
}

static const struct dev_pm_ops serial_pxa_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(serial_pxa_suspend, serial_pxa_resume)
};

static const struct of_device_id serial_pxa_dt_ids[] = {
	{ .compatible = "mrvl,pxa-uart", },
	{ .compatible = "mrvl,mmp-uart", },
	{}
};
MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);

/* Uart divisor latch write */
static void serial_pxa_dl_write(struct uart_8250_port *up, int value)
{
	unsigned int dll;

	serial_out(up, UART_DLL, value & 0xff);
	/*
	 * work around Erratum #74 according to Marvel(R) PXA270M Processor
	 * Specification Update (April 19, 2010)
	 */
	dll = serial_in(up, UART_DLL);
	WARN_ON(dll != (value & 0xff));

	serial_out(up, UART_DLM, value >> 8 & 0xff);
}


static void serial_pxa_pm(struct uart_port *port, unsigned int state,
	      unsigned int oldstate)
{
	struct pxa8250_data *data = port->private_data;

	if (!state)
		clk_prepare_enable(data->clk);
	else
		clk_disable_unprepare(data->clk);
}

static int serial_pxa_probe(struct platform_device *pdev)
{
	struct uart_8250_port uart = {};
	struct pxa8250_data *data;
	struct resource *mmres, *irqres;
	int ret;

	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	irqres = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (!mmres || !irqres)
		return -ENODEV;

	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(data->clk))
		return PTR_ERR(data->clk);

	ret = clk_prepare(data->clk);
	if (ret)
		return ret;

	uart.port.type = PORT_XSCALE;
	uart.port.iotype = UPIO_MEM32;
	uart.port.mapbase = mmres->start;
	uart.port.regshift = 2;
	uart.port.irq = irqres->start;
	uart.port.fifosize = 64;
	uart.port.flags = UPF_IOREMAP | UPF_SKIP_TEST;
	uart.port.dev = &pdev->dev;
	uart.port.uartclk = clk_get_rate(data->clk);
	uart.port.pm = serial_pxa_pm;
	uart.port.private_data = data;
	uart.dl_write = serial_pxa_dl_write;

	ret = serial8250_register_8250_port(&uart);
	if (ret < 0)
		goto err_clk;

	data->line = ret;

	platform_set_drvdata(pdev, data);

	return 0;

 err_clk:
	clk_unprepare(data->clk);
	return ret;
}

static int serial_pxa_remove(struct platform_device *pdev)
{
	struct pxa8250_data *data = platform_get_drvdata(pdev);

	serial8250_unregister_port(data->line);

	clk_unprepare(data->clk);

	return 0;
}

static struct platform_driver serial_pxa_driver = {
	.probe          = serial_pxa_probe,
	.remove         = serial_pxa_remove,

	.driver		= {
		.name	= "pxa2xx-uart",
		.pm	= &serial_pxa_pm_ops,
		.of_match_table = serial_pxa_dt_ids,
	},
};

module_platform_driver(serial_pxa_driver);

#ifdef CONFIG_SERIAL_8250_CONSOLE
static int __init early_serial_pxa_setup(struct earlycon_device *device,
				  const char *options)
{
	struct uart_port *port = &device->port;

	if (!(device->port.membase || device->port.iobase))
		return -ENODEV;

	port->regshift = 2;
	return early_serial8250_setup(device, NULL);
}
OF_EARLYCON_DECLARE(early_pxa, "mrvl,pxa-uart", early_serial_pxa_setup);
#endif

MODULE_AUTHOR("Sergei Ianovich");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pxa2xx-uart");
OpenPOWER on IntegriCloud